[GRASS-git] [OSGeo/grass-addons] 1bdb1d: i.zero2null (#206)

[Markus Metz]

  Branch: refs/heads/master
  Home:   https://github.com/OSGeo/grass-addons
  Commit: 1bdb1de637c9bf36953d4252eef266ae59c92868
      https://github.com/OSGeo/grass-addons/commit/1bdb1de637c9bf36953d4252eef266ae59c92868
  Author: Markus Metz <33666869+metzm at users.noreply.github.com>
  Date:   2020-06-13 (Sat, 13 Jun 2020)

  Changed paths:
    A grass7/imagery/i.zero2null/Makefile
    A grass7/imagery/i.zero2null/i.zero2null.html
    A grass7/imagery/i.zero2null/i.zero2null.py

  Log Message:
  -----------
  i.zero2null (#206)

fix nodata encoding for Sentinel-2 imagery, and possibly others
the value zero does not make sense for reflectance being the proportion of incoming light reflected back
zero is only possible for absolute black, all incoming light is completely absorbed (black holes can do that)